The author prospectively examined the power of persistent dissociation in predicting acute and chronic posttraumatic stress disorder symptoms (PTSD) in psychologists, psychotherapists, crisis intervention teams and clergymen after a disaster. 135 psychosocial disaster workers were assessed (6 weeks and 6 months after the catastrophe) with the Acute Stress Disorder Scale (ASDS), the Posttraumatic Stress Diagnostic Scale (PDS) and the German short version of the Dissociative Experience Scale (FDS-20). Correlational analysis and a hierarchical multiple regression analysis were conducted. Persistent dissociation and acute stress symptoms were correlated with later acute and chronic PTSD diagnosis. Together, persistent dissociation und acute stress symptoms accounted for 74 % (m)/36 % (w) of the acute and 58 % (m)/44 % (w) of the variance in PTSD symptoms. The results support that persistent dissociation is a main predictor of acute and chronic posttraumatic stress symptoms in disaster workers.